In the manufacture of paper and cardboard or other web-shaped materials and during drying processes on surfaces, corrosion, incrustations, adhesive contaminations, deposits and dirt accumulations frequently occur on rolls, cylinders and fabric covers. The types of deposits and their composition may be very diverse and heavily depends on the raw materials used, as well as the corresponding process materials. In the paper industry, one frequently encounters, e.g., adhesive contaminations that are referred to as “stickies.” The reasons for this type of deposits are usually the ingredients or constituents of the raw materials used. These usually consist of adhesives, binders and dispersants.
When primary fibers materials are used, for example, resin particles, fibers and paper dust can coat and clog cylinders, rolls and fabric covers and, in particular, reduce the porosity of the latter.
Among other things, deposits of any type on rolls, cylinders and fabric covers create problems during the manufacture. These problems result in standstill and cleaning times, production downtimes and output losses. Furthermore, deposits on drying cylinders used in the manufacture of paper or cardboard deteriorate the heat transfer and therefore cause significant energy losses during the drying process.
In the prior art, the deposits are removed during a machine standstill with the aid of cleaning chemicals, high-pressure cleaners and scrapers. Acidic and alkaline cleaning agents are used for this purpose. These cleaners can lead to corrosion, as well as infiltrate the bearing housings of the rolls and thusly lead to damages of the bearings. In addition, the utilization of these aggressive cleaning agents may, if applicable, be questionable with respect to occupational safety considerations and at least sufficient protective gear needs to be provided for the cleaning personnel.
When the components are sprayed with acidic and alkaline cleaners, the inhalation of the aerosols furthermore represents a health hazard for the personnel.
According to another option, the fabric covers, e.g., in a paper/cardboard machine or another system for manufacturing web-shaped materials are subjected to a continuous high-pressure cleaning process. In this case, water is sprayed on the fabric covers under high pressure. Deposits should be removed from the fabric covers in this way. One problem in this respect is the location of these units. At temperatures in excess of 100° C., the environment puts very high demands on the technology. This results in system failures and an increased service effort. Even undesirable remoistening of the web may occur. If the system fails, it can only be repaired again during a machine standstill. The fabric cover may become damaged due to the high water pressure. The service life of the fabric cover is therefore reduced.
A passivation product is sprayed on according to yet another option. However, this also requires a traversing nozzle. The ambient conditions also put very high demands on the technology in this case in order to prevent a failure of the nozzle. Only very little installation space is frequently available within the machine or another system for the manufacture of web-shaped materials. A certain cross section of the cross head is also required due to static requirements. However, the installation of the cross head then frequently interferes with other production operations.
Since the product is sprayed on from a certain distance and the cylinders and fabric covers rotate with very high peripheral speeds, significant atomization of the product occurs within the machine or another system. This leads to undefined spraying of the product within the machine. The aerosols being created may represent a health hazard for the personnel.
In consideration of this prior art, the present invention is based on the objective of at least partially eliminating the known disadvantages of the prior art.